Train annunciating apparatus



TRAIN ANNUNCIATING APPARATUS Filed March 25, 1938 Q 4 21 #3 2T 2; #4 5T 2 INVENTOR Ari/2a .Dodd.

BY w

HIS ATTORNEY Patented May 21, 1940 UNITED STATES PATENT OFFICE TRAIN ANNUNCIATING APPARATUS Application March 25, 1938, Serial No. 198,096

2 Claims.

My invention relates to. annunciating apparatus, and has particular reference to train annunciating apparatus for indicating at one point, such as an interlocking tower, the presence of a train at another point.

One feature of my invention is the provision of novel and improved apparatus for causing a steady indication to be displayed whenever a selected stretch of railway track is occupied, and for exhibiting a second indication the duration of which is dependent upon the will of the operator whenever a change occurs in the traffic conditions upon such stretch. A further feature of my invention is the provision of means to reduce the number of contacts required of the relay which controls the two indications, thus reducing the power requirements of the relay so that the relay may be operated over relatively long line circuits.

I shall describe two forms of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawing, Figs. 1 and 2 are diagrammatic views of two forms of apparatus each embodying my invention.

Referring to Fig. 1, the reference characters I and la designate the track rails of a stretch of railway track which are divided by means of the usual insulated track joints 2 to form a track section IT. Track section IT is provided with a track circuit comprising a suitable source of current, such as track battery 3, connected across the track rails at one end of the section and a track relay, designated as ITR, connected across the rails at the other end.

Located at an interlocking tower or other central control point is an annunciator IAK, which, as shown here, is a visual indicator in the form of an electric lamp, and a second annunciator IAX, which, as shown, is an audible indicator in the form of an electric buzzer. These annunciators are governed by a train controlled relay IAKR which is energized by a simple circuit including back contact 4 of relay ITR, and. connected with terminals B and C of a suitable source of energy. A manually operable switch or circuit controller IS cooperates with relay IAKR in controlling the second indicator IAX. Switch IS is provided with a movable contact member 5, which is operable to two positions, and with sets of contacts 66a and 'I-la. Contact 66a is closed when contact member 5 is in its normal position, that is, the position shown in the drawing, and contact 'I-'Ia is closed when contact member 5 is in its reverse position, that the indicator IAX becomes deenergized,

-IAX to terminal C. venergized so that its indication is no longer exis, the position the reverse of that shown in the drawing.

Under normal conditions, that is, when no train is present in the track section IT, relay ITR is energized; and relay IAKR, the first indicator 5 IAK and the second indicator IAX are deenergized.

When a train enters track section IT, relay ITR becomes deenergized and closes back contact 5 to complete the energizing circuit for relay 10 IAKR. Relay 'IAKR becomes energized and closes front contact 3 to complete a circuit passing from terminal B through front contact '8 of relay IAKR, and the filament of indicator IAK to terminal C; and to complete a circuit passing 15 from terminal B through front contact 8 of relay IAKR, contact 6-450; of switch IS, and the winding of indicator 'IAX to terminal C. Indicators IAK and IAX are now energized so that each indicator now exhibits its respective indication. The operation of the buzzer IAX warns the operator that a change in traflic conditions upon the stretch of railway has occurred, and the operation of lamp IAKindicates to the operator that section lT'has become occupied.

The operator may now operate the switch contact member '5 to its reverse position so that contact 6-6a is opened and contact 'I-Ia is closed. The opening of contact 6--6a opens the previously traced circuit for indicator IAX, and

Then, when the train vacates track section IT, relay ITR becomes, energized to open back contact 4 and open the energizing circuit for relay IAKR. Relay IAKR becomes deenergized to open front contact 8 to open the energizing circuit for indicator IAK, and to close back contact 9 to complete a second circuit for indicator IAX, which circuit passes from terminal B through back contact 9 of relay IAKR, contact 40 'I-ia of switch IS and the winding of indicator Indicator IAK is now de- -l-'Ia opens the second energizing circuit for indicator IAX; and, when contact 6-611 of switch I S closes, the apparatus is in its normal position.

Referring now to Fig. 2, which is a diagrammatic view of a second form of apparatus embodying my invention, the track rails l and la are divided into track sections 2T and 3T, which sections are provided with track circuits in a manner similar to that described for section IT in Fig. 1. Track relay 2TB. is included in the track circuit for section 2T, and similarly track relay 3TB is included in the track circuit for section 3T. A relay ZAKR is energized by a simple circuit including back contact ID of relay 2TB, and a relay SAKR. is energized by a simple circuit including back contact I I of relay 3TB. Although the track sections 2T and 3T are here disclosed as being adjacent sections, it will be understood that I do not limit myself to this one arrangement, and these sections, or a plurality of sections including these sections, may be otherwise disposed with respect to each other should it seem desirable.

Indicators ZAK and 3AK, which may be of the same form as indicator IAK referred to in Fig. and indicator 2AX, which may be of the same form as indicator IAX referred to in Fig. l, are provided at an interlocking tower or other central point. The indicators ZAK and (MK are controlled by the relays ZAKR and 3AKR, respectively. Manually operable switches or circuit controllers 2S and 3S, which may be of the same form as switch IS referred to in Fig. 1, cooperate with relays ZAKR and 3AKR, respectively, to control indicator 2AX. The reference characters 2R and SR designate asymmetrical units, that is, units in which the impedance to the flow of current in one direction is greater than for a flow of current in the other direction, which are associated with switches 23 and 3S,

respectively.

Normally, when no trains are within section 2T or 3T, relays 2TB and 3TR are energized; relays 2AKR and SAKR are deenergized; contact 6-611 of switch 28 and contact 66a of switch 38 are closed; and indicators ZAK, 3AK and 2AX are deenergized. Then, when a train traveling from left to right enters track section 2T, relay 2TB. becomes deenergized to close back contact In and complete the energizing circuit for relay ZAKR. Relay ZAKR picks up and closes front contact I2 to complete a circuit passing from terminal B through front contact I2 of relay ZAKR and the filament of lamp ZAK to terminal C; and to complete a circuit passing from terminal B through front contact I2 of relay ZAKR, contact 66a of switch 28, asymmetrical unit 2R. in the current conducting direction and the winding of indicator 2AX to terminal C. And, since indicators 2AK and ZAX are energized, they exhibit their respective indications. The operator may now operate movable contact member 5 of switch 25 to open contact 6--5a of switch 2S, which opens the previously traced circuit for indicator 2AX, and to close contact l--'Ia of switch 2S. Indicator ZAX now becomes deenergized and no longer exhibits its indication.

Then, when the train enters track section 3T, relay 3TB becomes released and closes back contact II to complete the energizing circuit for relay 3AKR. Relay 3AKR picks up to close front contact 43 and to complete a circuit passing from terminal B through front contact I3 of relay 3AKR and the Winding of indicator 3AK to terminal C; and to complete a circuit passing from terminal B through front contact I3 of relay 3AKR, contact 6-611 of switch 38, asymmetrical unit 3R in the current conducting direction, and the Winding of indicator ZAX to terminal C. As the indicators 3AK and ZAX are now energized, they exhibit their respective indications. The operator may now operate switch 38 to open contact 6-5a of switch 38, and to open the previously traced energizing circuit for indicator 2AX, and to close contact IIa of switch 3S.

Then, when the train vacates track section 2T, relay ZTR picks up to open back contact Ill and open the energizing circuit for relay ZAKR. Relay ZAKR releases to open front contact I2 to open the previously traced circuit for indicator ZAK, and to close back contact I4 to complete a circuit passing from terminal B through back contact I4 of relay 2AKR, contact 'I'Ia of switch 28, asymmetrical unit 2R in the current conducting direction, and the winding of indicator ZAX to terminal C. Indicator 2AX now becomes energized and exhibits its indication, while indicator EAK becomes deenergized and no longer displays its indication. The operator may now operate the switch 28 to open contact Ila of switch 28 and open the last traced circuit for indicator ZAX, and to close contact E6a of switch 2S.

When the train vacates section 3T so that relay 3TB. picks up to open back contact I I, the energizing circuit for relay BAKR is opened and relay BAKE becomes released. Front contact I3 of relay SAKR opens to open the previously traced energizing circuit for indicator 3AK, and back contact I5 of relay 3AKR closes to complete a circuit passing from terminal B through back contact I5 of relay 3AKR, contact 1-111 of switch 35, asymmetrical unit 3R in the current conducting direction, and winding of indicator 2AX to terminal C. Indicator 3AK now becomes deenergized and no longer displays its indication, and

indicator ZAX becomes energized to display its indication. The operator may now operate switch 38 to open contact 1-111 of switch 38 and to close contact 66a of switch 3S. The apparatus is now in its normal condition.

It is obvious that the apparatus of Fig. 2 will of the indicator ZAX and the switches 28 and 3S. respectively, so that current may flow from each switch to the winding of the indicator QAX, but current cannot flow in any appreciable amount from the winding of indicator ZAX to the respective switches. Thus, it can be seen that indicators ZAK and 3AK can only become energized by virtue of their respective energizing circuits including the front contact of the associated train controlled relay. It is to be noted further in each figure that the two indicators are controlled over dependent front and back contacts of the control relay.

It will be understood, of course, that my invention is not limited to the specific forms of annunciators described above and that such other forms may be selected as may be desirable to employ. As stated previously, my invention is not restricted to the track layout set forth in the description, the scope of my invention embracing a plurality of track sections each provided with a train controlled relay and an associated first indicator coacting with a single second indicator common to all of the relays in the manner set forth hereinbefore.

One advantage of apparatus embodying my invention is the provision of means for controlling separate indicators so that one indicator may exhibit a continuous indication, and the other indicator exhibit an indication for a period determined by the operator. A further advantage of my invention is that both indicators are controlled over front and back dependent contacts of a train controlled relay Previous to my invention, the control of the two separate indicators required independent contacts of the control relay. Since the apparatus embodied in my invention requires but a single movable contact member for each control relay, and since the power required to energize a relay is dependent upon the contact load imposed upon the relay, it can be seen that my invention provides means to reduce the power required to energize the control relay. Furthermore, since the power supplied to a relay is dependent upon line resistance of the line circuits, which resistance is in turn dependent upon the length of line circuits, it can be seen that the apparatus embodying my invention can be used with line circuits much longer than previously employed in the art.

Although I have herein shown and described only two forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination with a remotely controlled relay having two contacts a first of which is a front contact closed in the energized condition of the relay and the second of which is a back contact closed in the deenergized condition of the relay, a first indicator having an operating circuit including one of said two relay contacts, a second indicator having a first operating circuit also including said one relay contact and having a second operating circuit including the other of said two relay contacts, and a two position manually operable circuit controller interposed in said first and second operating circuits of said second indicator for selectively conditioning said second indicator for operation by said one or said other relay contact according as said circuit controller is in one or the other of its two positions, whereby said first indicator is operated during the interval said relay holds said one relay contact closed and said second indicator is operated upon a change in the condition of said relay until the circuit controller is actuated to terminate such operation and to condition said second indicator for operation upon further change in the condition of said relay 2. In combination, a plurality of separately controlled relays each having two contacts one of which is a front contact and the other of which is a back contact and which contacts are closed respectively in the energized and deenergized condition of the relay, a plurality of first indicators one for each of said relays, an operating circuit for each of said first indicators including one of said two contacts of the associated relay, a second indicator common to all of said relays, an operating circuit for said common indicator having a common portion connected with a plurality of pairs of alternate circuit paths one pair of such paths for each of said relays and each of such pairs of paths comprising a first path including said one contact of the associated relay and consequently having a portion thereof common with the operating circuit of the first indicator of such relay and a second path including the other of said two contacts of the associated relay, a plurality of two-position manually operable circuit controllers one for each of said relays and interposed in the associated pair of circuit paths of such relay for selectively conditioning said common indicator for operation by said one or said other contact of the associated relay according as the associated circuit controller is in one or another of its two positions, and a plurality of asymmetrical units one for each relay interposed in its associated pair of alternate paths and poled to prevent current fiow in such paths in the direction to eiTect operation of the first indicator associated with such relay.

ARTHUR E. DODD. 

